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3 years ago

Systems Working Together

Chemistry

1 answer:

gogolik [260]3 years ago

4 0

Answer:

Explanation:

Food moves through the digestive system with a wave-like motion called peristalsis. Muscles in the walls of the hollow organs contract and relax to cause this movement, which pushes food through the esophagus into the stomach.Apr 25, 2018

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Given that the density of TlCl(s) is 7.00 g/cm3 and that the length of an edge of a unit cell is 385 pm, determine how many form

ryzh [129]

Here's my best guess
the volume of the unit cell is (385*10^-12)^3=5.7066*10^-29 m^3
multiply by density to get mass mass = (7 g/cm^3)*(100^3 cm^3 / 1^3 m^3) * 5.7066*10^-29 m^3= 3.99466*10^-22 g
covert to moles 3.99466*10^-22 g * 1 mol / 239.82 g = 1.6657 *10^-24 mol
convert to number of units

1.6657 *10^-24 mol * 6.23*10^23 units/mol = 1.04

385 pm = 3.85*10^(-8) cm

The volume of the unit cell is the cube of that, which is 5.71*10^(-23) cm^3. Since the ratio of mass to volume (i.e. the density) must be the same no matter what amount of TlCl you have, you can say:
7 = x/(5.71*10^(-23)), where x is the mass of the unit cell. Solving for x, you get 4*10^(-22) g.

The mass of a molecule of TlCl is 240 amu, which in grams is 4*10^(-22) g. The mass of the unit cell and the mass of a molecule of TlCl is the same. Therefore there is one formula unit of TlCl per unit cell.

3 0

4 years ago

The story of space exploration began with unmanned exploration, moved into a period of manned exploration, and now appears

katovenus [111]

Answer:

appears to be moving back toward unmanned exploration in the form of deep-space satellite exploration.

Explanation:

NASA moved from unmanned probing of space in its initial stage of space exploration to manned space exploration and moon landing and now has gone back to unmanned exploration into deeper space. Deep space is not completely known yet, and the exploration take year and are probably very dangerous for manned exploration for now.

6 0

4 years ago

Read 2 more answers

Consider 2 NOCl(g) \Longleftrightarrow⟺ 2 NO(g) + Cl2 (g) At 25oC under conditions other than equilibrium, there are 1.20 moles

nekit [7.7K]

Answer:

a) Q = 6.1875x10⁻³

b) The direction of the reaction is to form the products.

c) [Cl₂]e = 0.094 M

[NO]e = 0.190 M

[NOCl]e = 0.140 M

Explanation:

a) Q is the reaction quotient, and for a generic reaction aA + bB ⇄ cC + dD it is

$Q = \frac{[C]^cx[D]^d}{[A]^ax[B]^b}$

Which is the same equation for Kc, but in Kc expressions, the concentrations are in the equilibrium. Q is calculated at any time. So, for the reaction given

2NOCl(g) ⇄ 2NO(g) + Cl2(g)

$Q = \frac{[Cl2]x[[NO]^2}{[NOCl]^2}$

[Cl₂] = 0.220/5.00 = 0.044 M

[NO] = 0.450/5.00 = 0.090 M

[NOCl] = 1.20/5.00 = 0.240 M

Q = (0.044)x(0.090)²/(0.240)²

Q = 6.1875x10⁻³

b) Q < Kc, which means that there are fewer products to what are needed to the equilibrium. So the direction of the reaction is to form the products.

2NOCl(g) ⇄ 2NO(g) + Cl2(g)

0.240 0.090 0.044 Initial

-2x +2x +x Reacts (stoichiometry is 2:2:1)

0.240-2x 0.090+2x 0.044+x Equilibrium

$Kc = \frac{(0.044+x)x(0.090+2x)^2}{(0.240 - 2x)^2}$

$1.86x10^{-1} = \frac{(0.044+x)*(8.1x10^{-3} +0.36x + 4x^2)}{(0.0576 - 0.96x +4x^2)}$

3.564x10⁻⁴+0.01584x+0.176x²+8.1x10⁻³x+0.36x²+4x³ = 0.010714-0.17856x+0.744x²

4x³ - 0.208x² + 0.2025x - 0.01036 = 0

Solving this third grade equation in a computer program:

x = 0.05 M

So:

[Cl₂]e = 0.044 + 0.05 = 0.094 M

[NO]e = 0.090 + 2x0.05 = 0.190 M

[NOCl]e = 0.240 - 2x0.05 = 0.140 M

7 0

3 years ago

How many molecules are in 3.94g of SO2?

IRISSAK [1]

To find the number of molecules, you need to first convert the mass into number of mol using the molar mass of SO2, simply add the atomic masses of each element and the number of times each element appears in the formula from the periodic table.

Then divide the mass by that value and then use Avogadro’s number to find the molecules.

Multiply by 6.02 x 10^23 Molecules.

5 0

4 years ago

Identify six stages of the process of scientific inquiry (scientific method) and explain why the process is not a rigid sequence

I am Lyosha [343]

Purpose- state the problem
research- find out about the topic
hypothesis- predict the outcome of the problem
expiriment- develop a procedure to test the hypothesis
conclusions-compare the hypothesis t ok the outcome of the experiment

7 0

3 years ago